Detection and quantification of genetically engineered crops

Genetically modified organisms (GMOs) have recently attracted the attention of agricultural, medical and food scientists and governments of many countries in the world due to an increasing concern that the recombinant gene(s) inserted into an organism may result in unforeseen effects. Therefore, there is a need to regulate each transgenic event so that the officially approved events will be the only products for commercial use. However, for controlling the unauthorized use of the unregulated transgenic events, their early detection is necessary. These detection methods are primarily based on identifying the inserted DNA sequence (DNA-based techniques) or the specific proteins resulted from the inserted gene (protein-based techniques). The DNAbased techniques are currently the major detection methods that are widely used due to their ease and accuracy. However, detection for the presence or absence alone is not sufficient for regulation of GMOs. Rather, identification of the transgenic event (authorized or not) and their amount in a given lot should also be quantified to determine the threshold level. Hitherto, PCR (polymerase chain reaction)-based approaches are the most reliable methods for the quantification of genetic modification both in raw as well as processed products. For every country expected to use genetically engineered crops or food products resulted from them, detection and quantification capacity should be readily available.